diff --git a/Makefile b/Makefile
index 356fcf40487e93..d826f56edd3ad5 100644
--- a/Makefile
+++ b/Makefile
@@ -300,7 +300,7 @@ jstest: build-addons build-js-native-api-tests build-node-api-tests ## Runs addo
 
 .PHONY: tooltest
 tooltest:
-	@$(PYTHON) test/tools/test-js2c.py
+	@$(PYTHON) -m unittest discover -s ./test/tools
 
 .PHONY: coverage-run-js
 coverage-run-js:
diff --git a/test/tools/test-js2c.py b/test/tools/test_js2c.py
similarity index 100%
rename from test/tools/test-js2c.py
rename to test/tools/test_js2c.py
diff --git a/tools/gyp/pylib/gyp/MSVSSettings_test.py b/tools/gyp/pylib/gyp/MSVSSettings_test.py
index bf6ea6b802ff91..245478c8dae4ed 100755
--- a/tools/gyp/pylib/gyp/MSVSSettings_test.py
+++ b/tools/gyp/pylib/gyp/MSVSSettings_test.py
@@ -6,15 +6,19 @@
 
 """Unit tests for the MSVSSettings.py file."""
 
-import StringIO
 import unittest
 import gyp.MSVSSettings as MSVSSettings
 
+try:
+  from StringIO import StringIO  # Python 2
+except ImportError:
+  from io import StringIO  # Python 3
+
 
 class TestSequenceFunctions(unittest.TestCase):
 
   def setUp(self):
-    self.stderr = StringIO.StringIO()
+    self.stderr = StringIO()
 
   def _ExpectedWarnings(self, expected):
     """Compares recorded lines to expected warnings."""
diff --git a/tools/gyp/pylib/gyp/common.py b/tools/gyp/pylib/gyp/common.py
index e5ebcd9c9f2f06..351800ee25e23e 100644
--- a/tools/gyp/pylib/gyp/common.py
+++ b/tools/gyp/pylib/gyp/common.py
@@ -2,7 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import collections
 import errno
 import filecmp
 import os.path
@@ -10,6 +9,11 @@
 import tempfile
 import sys
 
+try:
+  from collections.abc import MutableSet
+except ImportError:
+  from collections import MutableSet
+
 
 # A minimal memoizing decorator. It'll blow up if the args aren't immutable,
 # among other "problems".
@@ -493,7 +497,7 @@ def uniquer(seq, idfun=None):
 
 
 # Based on http://code.activestate.com/recipes/576694/.
-class OrderedSet(collections.MutableSet):
+class OrderedSet(MutableSet):
   def __init__(self, iterable=None):
     self.end = end = []
     end += [None, end, end]         # sentinel node for doubly linked list
diff --git a/tools/gyp/pylib/gyp/easy_xml_test.py b/tools/gyp/pylib/gyp/easy_xml_test.py
index df64354982c01d..664b538a58db60 100755
--- a/tools/gyp/pylib/gyp/easy_xml_test.py
+++ b/tools/gyp/pylib/gyp/easy_xml_test.py
@@ -8,13 +8,17 @@
 
 import gyp.easy_xml as easy_xml
 import unittest
-import StringIO
+
+try:
+  from StringIO import StringIO  # Python 2
+except ImportError:
+  from io import StringIO  # Python 3
 
 
 class TestSequenceFunctions(unittest.TestCase):
 
   def setUp(self):
-    self.stderr = StringIO.StringIO()
+    self.stderr = StringIO()
 
   def test_EasyXml_simple(self):
     self.assertEqual(
diff --git a/tools/gyp/pylib/gyp/generator/msvs_test.py b/tools/gyp/pylib/gyp/generator/msvs_test.py
index c0b021df502bfa..1b0cdd17201d5b 100755
--- a/tools/gyp/pylib/gyp/generator/msvs_test.py
+++ b/tools/gyp/pylib/gyp/generator/msvs_test.py
@@ -7,13 +7,17 @@
 
 import gyp.generator.msvs as msvs
 import unittest
-import StringIO
+
+try:
+  from StringIO import StringIO  # Python 2
+except ImportError:
+  from io import StringIO  # Python 3
 
 
 class TestSequenceFunctions(unittest.TestCase):
 
   def setUp(self):
-    self.stderr = StringIO.StringIO()
+    self.stderr = StringIO()
 
   def test_GetLibraries(self):
     self.assertEqual(
diff --git a/tools/gyp/pylib/gyp/generator/ninja_test.py b/tools/gyp/pylib/gyp/generator/ninja_test.py
index 1767b2f45a04ca..c8adc251c97d50 100644
--- a/tools/gyp/pylib/gyp/generator/ninja_test.py
+++ b/tools/gyp/pylib/gyp/generator/ninja_test.py
@@ -6,11 +6,10 @@
 
 """ Unit tests for the ninja.py file. """
 
-import gyp.generator.ninja as ninja
-import unittest
-import StringIO
 import sys
-import TestCommon
+import unittest
+
+import gyp.generator.ninja as ninja
 
 
 class TestPrefixesAndSuffixes(unittest.TestCase):